Convert any* string to kebab-case or snake_case

main.py

import re


def delimited_case(s: str, *, delimiter: str) -> str:
    return re.sub(
        r"(([a-z0-9])(?=[A-Z][a-zA-Z0-9])|([A-Z0-9])(?=[A-Z0-9][a-z]))",
        rf"\1{delimiter}",
        re.sub(r"[^a-zA-Z0-9]+", delimiter, s),
    )


def kebab_case(s: str) -> str:
    return delimited_case(s, delimiter="-").lower()


def snake_case(s: str) -> str:
    return delimited_case(s, delimiter="_").lower()


def screaming_case(s: str) -> str:
    return delimited_case(s, delimiter="_").upper()


print("| `s` | `kebab_case(s)` | `screaming_case(s)` |")
print("|-----|-----------------|-----------------|")
for s in [
    "kebab-case",
    "snake_case",
    "PascalCase",
    "PascalCaseWithURL",
    "PascalCaseWithURLInTheMiddle",
    "camelCase",
    "camelCaseWithS3Bucket",
    "separate words with S3Bucket",
    "Really_weird-mixOfDifferent.cases",
]:
    print(f"| {s} | {kebab_case(s)} | {screaming_case(s)} |")

s	kebab_case(s)	screaming_case(s)
kebab-case	kebab-case	KEBAB_CASE
snake_case	snake-case	SNAKE_CASE
PascalCase	pascal-case	PASCAL_CASE
PascalCaseWithURL	pascal-case-with-url	PASCAL_CASE_WITH_URL
PascalCaseWithURLInTheMiddle	pascal-case-with-url-in-the-middle	PASCAL_CASE_WITH_URL_IN_THE_MIDDLE
camelCase	camel-case	CAMEL_CASE
camelCaseWithS3Bucket	camel-case-with-s3-bucket	CAMEL_CASE_WITH_S3_BUCKET
separate words with S3Bucket	separate-words-with-s3-bucket	SEPARATE_WORDS_WITH_S3_BUCKET
Really_weird-mixOfDifferent.cases	really-weird-mix-of-different-cases	REALLY_WEIRD_MIX_OF_DIFFERENT_CASES